Simulated Response of Acoustic Log in Horizontal Borehole Placing on Interface of Two Formations

Based on numerical calculation of wave equation with high-order 3D staggered-grid finite difference method,simulated is the acoustic wavefield in borehole whose axis is placed on interface of two isotropic formations with different sonic velocities,and presented are acoustic wave forms received at different transmitter-receiver spacings and snapshots of acoustic wavefield at different times.Analyzed result shows that wherever which formation covering on the top of the other,the wavefield is more sensitive to the formation with faster sonic velocity,every slowness of first wave arrival received in borehole is very close to the slowness of the formation with faster compressional wave velocity.The result provides a basic reference for data process and interpretation of acoustic logging in horizontal well.